TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E10E471 Panasonic	VARISTOR 470V 4.5KA DISC 11.5MM	0
ERZ-V20D431 Panasonic	VARISTOR 430V 10KA DISC 20MM	0
ERZ-U22JP132F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-CF2MK361 Panasonic	VARISTOR 360V 200A 2SMD JLEAD	1856
ERZ-V07D151 Panasonic	VARISTOR 150V 1.75KA DISC 7MM	1624
ERZ-U23JP192F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E08A221CS Panasonic	VARISTOR 220V 3.5KA DISC 10.5MM	0
ERZ-V10D511 Panasonic	VARISTOR 510V 3.5KA DISC 10MM	0
ERZ-V10D821 Panasonic	VARISTOR 820V 3.5KA DISC 10MM	757
ERZ-V20D821 Panasonic	VARISTOR 820V 7.5KA DISC 20MM	0
ERZ-E10B241CS Panasonic	VARISTOR 240V 4.5KA DISC 11.5MM	0
ERZ-E11A102 Panasonic	VARISTOR 1KV 5KA DISC 13MM	949
ERZ-V20D911 Panasonic	VARISTOR 910V 7.5KA DISC 20MM	1390
ERZ-C20EK781Y Panasonic	VARISTOR 780V 8KA MODULE	20
ERZ-U22JP162F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E10B621CS Panasonic	VARISTOR 620V 4.5KA DISC 12.50MM	0
ERZ-E11A431 Panasonic	VARISTOR 430V 6KA DISC 13MM	71018
ERZ-E08A751 Panasonic	VARISTOR 750V 3.5KA DISC 11.5MM	547
ERZ-U21JP162F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-V05D331 Panasonic	VARISTOR 330V 800A DISC 5MM	899

TVS - Varistors, MOVs

1. Overview

Transient Voltage Suppressors (TVS), Varistors, and Metal Oxide Varistors (MOVs) are critical components for protecting electronic circuits from voltage spikes and electrostatic discharge (ESD). These devices clamp excessive voltage to safe levels, preventing damage to sensitive components. TVS diodes are semiconductor-based solutions with fast response times, while Varistors (including MOVs) use nonlinear resistive materials to absorb energy. Their importance spans industries like telecommunications, automotive, and consumer electronics, ensuring reliability in environments exposed to electrical surges.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
TVS Diodes	Unidirectional/bidirectional clamping, sub-nanosecond response time, low leakage current	Communication interfaces (USB, HDMI), microcontrollers, power supplies
Zinc Oxide Varistors	High energy absorption, voltage-dependent resistance, aging characteristics	Power line protection, industrial motor drives, surge protection strips
MOVs	Specialized varistors with metal oxide ceramics, optimized for AC/DC applications	Appliances, LED lighting, renewable energy systems

3. Structure and Composition

TVS diodes employ a PN junction semiconductor structure with doping profiles optimized for breakdown characteristics. Varistors consist of polycrystalline ceramic materials (typically zinc oxide grains with additives) sandwiched between metal electrodes, encapsulated in epoxy or molded housings. MOVs use similar materials to varistors but with enhanced grain boundary engineering for improved voltage clamping. All devices incorporate termination coatings (e.g., silver, tin) for PCB mounting compatibility.

4. Key Technical Parameters

Parameter	Description	Importance
Clamping Voltage (V_CLAMP)	Voltage level during surge conduction	Determines protection level for downstream components
Response Time	Time to transition from blocking to clamping mode	TVS: 0.5-10 ns; MOVs: 10-50 ns
Energy Absorption (W_ADM)	Maximum surge energy handling capability	Measured in joules (J), critical for industrial applications
Leakage Current	Off-state current at rated voltage	Impacts power efficiency, typically <100 A

5. Application Fields

Key industries include:

Consumer Electronics: Smartphone charging circuits, TV power supplies
Industrial Automation: PLCs, motor drives, sensor interfaces
Automotive: ECU protection, CAN bus interfaces, battery management systems
Renewable Energy: Solar inverters, wind turbine controllers

Case Study: MOVs in smart meters provide 10kA surge protection against grid transients.

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Specifications
Littelfuse	SM712-02	12A, 13.3V clamping, bidirectional TVS for RS-485
Bourns	V14450A	14mm MOV, 450VAC, 210J energy rating
STMicroelectronics	TV05C060	0.5W, 6V, ultra-small TVS for IoT devices

7. Selection Guidelines

Key considerations:

Operating voltage vs. clamping voltage margin
Surge current requirements (8/20 s waveform standard)
Package size constraints (SMD vs. through-hole)
Environmental conditions (temperature, humidity)
Lifespan expectations (MOVs degrade with repeated surges)

8. Industry Trends

Emerging trends include:

Miniaturization: Sub-0201 TVS devices for mobile applications
Higher energy density: MOVs with >1000J/cm absorption
Integration: Combined ESD and surge protection solutions
Automotive focus: AEC-Q qualified devices for 48V systems
Green manufacturing: Lead-free and RoHS-compliant materials